关键词: 势接触力, 接触判断, NMM, FEM-DEM

Abstract: Contact treatment of the numerical manifold method (NMM) mainly includes contact detection, including point-point and point-line contact, open-close iteration for determining the correct constrained state, and contact transfer by which effective contact couples can be transferred to the next time step. The whole process is slightly complicated and inefficient. Besides, the contact modes adopted in the NMM are quite different from the real physical contact state. The no binary search (NBS) contact detection algorithm proposed by Munjiza maps all elements into regular cells and connects the elements by the list structure effectively. The contact detections are limited within the cell and the four neighboring cells. With low requirement of random access memory, contact detection operation is just proportional to the number of the elements, and the efficiency is accordingly increased significantly. With the defined ‘potential’, contact pressure, belonging to the distribution category, is calculated by the contact overlapped area, which is closer to the real contact state, and avoids the cumbersome process involved in the NMM. As a result, it is introduced to the NMM as an alternative contact treatment method. The effectiveness is verified by the examples.

Key words: potential contact force, contact detection, numerical manifold method (NMM), FEM-DEM